Interaction Effect And Mechanism Of The Aromatic Rice And The Main Rice Pests

Aromatic rice contains scented substances.It is often planted as late single-season rice.Because the characteristics of aromatic rice are particularly different from ordinary (quality) rice,and the cropping patterns has been changed into late single-season rice. Ecological status in the rice paddy is bound to change a lot.This lead to the occurrence of major pests(Chilo suppressalis,Cnaptalocrocis medinalis,Nilaparvata lugens) in rice changes accordingly.Old forecasting methods can not applied directly to pests on aromatic rice.In this paper,EX-1 and WX-988 were used to survey occurrence characteristics of the main rice pests on aromatic rice.The fitness of aromatic rice to major pests,as well as the impact of aromatic rice morphology and biochemical characteristics on the fitness was studied,In all the experiments,ordinary(non-aromatic) rice LYP-9 and EZ-5 were used as control.These results can be used to guide the main pests management for aromatic rice and further service to the aromatic rice production. Main results are as follows:1.Through field and laboratory experiments found that field major pests and community structure of natural enemies in aromatic rice paddy was similar to which in ordinary rice paddy,but difference on the dynamics and stability of the community structure between aromatic and ordinary rice existed and changed with time.Pests community structure on EX-1 were more stable than that on ordinary rice,but on aromatic rice WX-988 was vise visa.2.The peak density of the three major rice pests in paddy of aromatic rice was significantly higher than ordinary rice;different seeding period was associated to different pest species.In single season cultivation,extent of the incidence and danger of C.suppressalis was higher when compared with other serious pests.This is so for the same varieties cultured for single season rice and late single-season rice3.The fitness of aromatic rice to C.suppressalis,C.medinalis,and N.lugens was higher than ordinary rice.The index of the general population trend of and the offspring adults of N.lugens female on ordinary rice was higher than on ordinary rice.The rate of larvae survival pupation emergence and the amount of egg of C.medinalis on aromatic rice was higher than ordinary rice.4.Silicon cell density on sheath surface of WX-988 were lower than LYP-9,but they were significantly higher than EX-1 and EZ-5.Higher invasive rate of C. suppressalis borer was found on varieties,EX-1 and EZ-5,with lower silicon cells density by comparison.Sheath ridge height,medullar cavity diameter,spacing vascular significantly different among varieties,but with the borer larvae survival rate and invasive were not necessarily linked.WX-988 plant taller than the others,leaves wider than the others,higher egg density than others were found during the oviposition peak of C.medinalis.C.medinalis spawning peak,chlorophyll content of EX-1 lower than other varieties,but eggs density just lower than WX-988.EX-1 with significantly different biochemical characteristics,namely at tilling stage sugar and amino acid content lower than other varieties,and with the ever-increasing plant growth process,to boot stage higher than other varieties,the C.suppressalis damage rates showed the same trend.At tillering stage Blight heart rate caused by C.suppressalis lower than that of other varieties,but at heading and filling stage,it is higher than that of EZ-5 and LYP-9.Spawning cage experiments show that C.suppressalis females layed more egg on EX-1.More N.lugens macropterous female,C.medinalis borers and C medinalis larvae move towards aromatic rice between aromatic and ordinary rice,between the two kinds of fragrant rice is not significant,Aromatic Rice Leaf Roller larvae of volatile compounds from actors should be higher than that of non-scented rice,but the difference was not significant.Temperament linked rice ice volatile components analysis,and EX-1 peak at the most,followed by the WX-988,and EZ-5 andLYP-9, different varieties retention time of the same components in different peaks order.All results above showed that:under natural conditions,the population of C. medinalis,C.suppressalis,and N.lugens in aromatic rice field were higher than that in ordinary rice paddy,and changed along with the growing season adjusting.The volatile components extracted from the aromatic rice had obvious attraction to the pest.The aromatic rice was more fitness to these three rice pests than ordinary rice.Amino acids and sugar content,silicon cell density of sheath epidermal,and morphology were important factors influencing the occurrence of these three pests on aromatic rice.